Drilling machine



July 10,1928. 1,676,461

I A. E. ROBINSON ET AL DRILLING MACHINE Filed Aug. 20, 1926 5 Sheets-Sheet 1 DRILLING MACHINE 5 Sheets-Sheet 2 Filed Aug 20, 1926 I39 o 131 "I m m l 3 July I0, .1928. 1,676,461

A. E. ROBINSON ETAL v DRILLING MACHINE Filed Aug. 20. 1926 5 Sheets-Sheet 4 u I 'r I July 10, 1928. 1,676,461

A. E. ROBINSON ET AL DRILLING MACHINE Filed Aug. 20, 1926 5 Sheets-Sheet 5 Patented July 10, 1928.

PATENT ALBERT E. ROBINSON AND AUGUSTUS M. SO SA, OF CINCINNATI, OHIO, ASSIGNORS TO THE AMERICAN TOOL WORKS COMPANY, OF CINCINNATI, OHIO, A CORPORATION OF OHIO.

DRILLING MACHINE.

Our invention relates to drilling machinery. especially to that type known as radial drilling machines.

It is the object of our invention to provide new and improved means whereby the drill-arm is held in adjusted positions; further to provide means for operating a clamp and braking means for said operating means; further, to provide operating means for a drill-arm clamp comprising a driving member. control means for the latter, and novel means for maintaining said driving member in driving relation to insure completion of a sequence of operations in said clamping means and prevent overthrow in the same; further, to provide a releasable driving connection for the clamping means and breaking means interconnected for sequential operation; further, to provide driving means for a drill-arm clamping means, a releasable driving connection therein, and braking means for said driving means comprising centrifugal means for moving said braking means into braking relation, and means acting in synchronism with the cycles of operation of said clamping means acting to release said driving connection and said resistance to said centrifugal means for braking relation in said brake; and, further, to provide control means for the latter, to maintain said driving connection and resist said. centrifugal means whereby to insure completion of a cycle of movement in said clamping means.

It is the object of our invention, further, to provide means acting on the driving force for the driving member for reducing or stopping said driving force at each clamp actuation; further, to provide means operatively connected with the clamp for releasing, the driving member, reducing or stopping the driving force for said driving member, and braking said driving member, respectively: and further, to provide means for returning said last-named means to normal relations.

Our invention will be further readily un- Fig is a horizontal axial section, taken on the line 5+5 of Fig. 1. Fig. 6 is a cross-section, taken in the plane of the line 6.6 of Fig. 5.

Fig. 7 is a vertical cross-section taken on the line 77 of Fig. 3.

F 8 is a detail of the same, shown in cross-section on the line 8-8 of Fig. 3.

' Fig. 9 is a cross-section, taken in of the line .9-9 of Fig. 5

' Fig. 10 is an axial section of a detail, taken on the line 1010 of Fig 5.

" Fig. 11 is a vertical section of the clamp In" mechanism, taken on the line 11-11 of F ig. 3. i

Fig. 12 is a. detail in horizontal section, taken in the line 1212 of Fig. 11.

Fig. 13 is aplan view partly in section showing the clamping means and operating means therefor in unclamped relation.

Fig. 14: is a similar view showing the parts in clamped relation.

' Fig. 15 is a. cross-section of a detail taken on the line 15-15 of Fig. 2, showing one of the electric connections- Fig. 16 is a cross-section of'the same taken ijnthe plane of the line 1616 of Fig. 15. Fig. 17 is a diagrammatic View of electric c rcuits for operation of our improved device.

Our present invention is an improvement upon the invention shown, described and clalmed in our copending application for patent on improvement in drilling machines, filed by us in the United States Patent Oflice June 27, 1924, Serial No. 722,857, and issued as Patent No. 1,600,847, dated September 21, 1926.

We have exemplified our invention on a drilling machine comprising a base 21, from which a stationary post 22 extends upwardly, about which there is a rotatable column 23, having suitable bearings about the post in suitable 'manner, one of which bearings is exemplified at 24. The post is usually integral with the base. A drill-arm exthe plane I b'll said check and said nut.

tends laterally from the column and is adjustable to elevation thereon by slide connection between its bearing 26 and the outer periphery of the column, the adjustment being usually by means of an adjusting screw 27 having threaded connection with a suitable nut on the arm, relative rotation between the screw and the nut, being effected by suitable means for raising or lowering of the drill-arm.

The drill-arm carries a suitable drill-s1ide 31, adjustable laterally thereon on guideways 32, extending lengthwise of the drill-v arm, the adjustment being exemplified as effected by a suitable rack 34 on the drillarm, with which a suitable pinion mounted on the drill-slide meshes, the pinion being suitably operated, as by a train of gearing operated by handles 35, 36, on the drillslide.

A suitable drill-spindle 37 is journaled on the drill-slide and is arranged to have a suitable drill 38 secured thereto, suitable means being provided for axially feeding the drillspindle.

In the present exemplification, the column is rotatable on the base for the purpose of adjustment of the drill-arm into suitable radial positions with relation to the base, for coaction of the drill-spindle with work on a suitable work-support 39 extending from the base, or with work arranged around the column in well-known manner.

The drill-arm is arranged to be clamped in suitable adjusted radial positions, effected in the present instance by clamping the column to the base. For accomplishing this the column has a split bearing 41 about a lower journal part 42 of the post. The split bearing is arranged to be clamped about the post by means of an eccentric 43 on a shaft 44: journaled in bearings 45, 46, located in lugs on said split bearing, at one side of the split thereof. A link 47 has a bearing 48 about said eccentric and extends through an aperture 49 in a cheek 50 formed as a lug at the other side of said split, and adjustable with relation thereto by means of a nut 51 threaded over the threaded end 52 of said link, a washer 53 being shown between (See Figs. 11 and 12.)

The eccentric is arranged to be rotated, shown accomplished in the present exemplification by an arm 55 secured to said shaft, and means for swinging said arm. The connection between said arm and said shaft is preferably adjustable, as by providing a cone-clutch connection 56 between them, with a nut 57 received over the threaded end 58 of said shaft for clamping said arm to said shaft. (See Fig. 11.)

The eccentric is operable for drawing said split hearing about the post and clamping it to the base, and locking relation being preferably such that a right line, exemplified at 0, drawn through the high point 62 of the eccentric and the axis of rotation 63 of the shaft, will be parallel with the link 47 or the line of clamping force exerted between the cheeks at the respective sides of the split bearing, whereby such split bearing is maintained or locked in clamped relation. (See Figs. 13 and 14.) In such relation an exterior force is required to disturb the clamping relation of the eccentric.

A movement of the eccentric so that its high point is moved away from said right line will cause an unclamping movement in the clamp bearing, due to the natural resiliency in the metal of said bearing, for releasing its clamping hold upon the post'. The extent of such movement is optional, the unclamping movement of the eccentric being indicated in dotted lines in Fig. 13. Such movement of the eccentric is accomplished by-a movement of the arm 55 into the position shown in Fig. 13. The the high point of the eccentric with relation to the axis of rotation of the shaft 44 is then as shown in Fig. 13.

The rotation of the eccentric is in the present instance accomplished by a crank comprising a crank-pin 67 and a crank-arm 68 having an axis of rotation 69, and ex emplified as rotated by a gear 7 O, rotatable about a stud-shaft 71 fixed in a bearing 72 of a gearbox 73 on a bracket 74 extending from the column. The arm exemplified as fixed to a hub 75 extending from said gear, being, for instance, keyed thereto by a key 76, and held to said hub by a flange 77 on said stud-shaft. (See Fig. 7.)

A link 78 is articulated at one of its ends about the crank-pin and is at its other end articulated with the arm 55 by a pin 79.

The gear 70 is shown as a worm gear and as engaged by a worm 81 fixed to a shaft 82, journaled in bearings 83, 84, of said gearbox (see Figs. 5 and 10). Other means than those described may be employed for rotating the crank-pin. The means acting on the crank-pin are preferably such as to hold the crank-pin in the position in which it is located upon cessation of rotation of the gear. Thus the worm. forms a lock upon the worm-wheel for holding the worm-wheel nonrotative during idle relation of the worm.

A drive-shaft 85, is journaled in bearings 86, 87, of a housing 88, fixed to the bracket 74, as by bolts 89. The means exemplified for rotating the drive-shaft is an electric motor 91 fixed to the bracket 74, the rotor 92 of which is provided with a shaft 93, connected with the drive-shaft by any suitable driving connection indicated at 94, placed between said rotor and said driving shaft.

A power connecting and disconnecting couple, exemplified as a clutch 101, is loosition ofill] lift) cat-ed between the drive-shaft and the shaft 82, and means are provided for engaglng and disengaging said clutch. The clutch is exemplified as normally in clutched relation. The'clutch is exemplified as comprising a collar 102 fixed to the shaft 82, and a collar 103 slida-ble endwise on a. sleeve 10% and having spline groove and key connection 105 with said sleeve. (See Figs. 5 and 10.) Said clutch is exemplified as a toot-hclutch', the teeth of which are on the proximate ends of said collars, said collars representing the members of a power connecting and disconnecting couple, which couple may, however, be of other form and be any suitable power connecting and disconnecting couple, for connecting the power between the driveshaft and the crank.

The clutch is exemplified as rotating in the direction of the arrow 7) in Fig. 5. The clutch-teeth preferably have coacting abrupt faces 106 at one of their respective sides and inclined faces 107 at the other of their respective sides, whereby the teeth of the movable clutch-collar are arranged to slide into the tooth-spaces between the teeth of its mating clutch-collar when contact has once been made between the ends of the clutchteeth.

Means are provided for controlling the engaged and disengaged relation in the clutch, shown as automatically acting means, the clutch being shown normally engaged, in order that when rotation of the drive-shaft takes place, its rotation is communicated without clash or jar to the crank.

Means are also provided for maintaining rotation of the drive shaft during a sequence of operations in the clamping means.

Means are further provided for causing cessation of rotation of the rotary driving member after substantial completion of said cycle of operations in the clamping means, so as to limit the movement of the clamping means at any one time to a single cycle of .movements, preferably either for clamping relation or for unclamping relation of the clamping means.

The clamping movement and the unclamping movement of the clamping means take place in sequence, and each movement of the clamping means is limited to either a clamping movement or an unclaniping movement, in the present exemplification.

The means are further provided so that an operator, when he moves the control for a cycle of movements in the clamping means, is assured of the completion of said cycle of movements, and means are provided so that he cannot interrupt said completion or compel a control movement which will in terfere with an uncompleted control effect previously initiated and not yet completed.

A lever 111 is provided with arms 112, 113

forming a fork, provided with pivoted shoes 115 received in an annular groove 116 in the collar 103 of'the clutch. The sleeve 10 i is fixed to the shaft 85, as by a key 119.

The lever is pivoted on a pivot-rod 121 fixed in a bearing 122 on the brackets 7%, the rod being held in said bearing between a flange 123 on said rod and a nut 124. at the respective ends of said bearings. A collar 125 fixed to the rod holds the lever on said rod.

The arm 112 has a roller 126 journaled on a stud-pin 127 fixed in a bearing 128 of said arm.

Said lever is also provided with an arm 131. A latch-rod 132 is slidable endwise in a bearing 133 of the housing 88, and is prevented from turning therein. A collar 13 l is fixed to said latchrod, and is provided with a slot 135 in which a shoe 136 having a stem 137 journalcd in a bearing 138 of the arm 131 is received. Pivotal movement of the lever 111 on its pivot causes endwise movement of the latch-rod 132. I

The lever 111 is further provided with an arm 139 upon which a spring 140 acts to normally move said lever into clutching relation of the clutch. The spring is received about a stem 141 fixed to the'gearbox 73, and about a thimble 142, received over said stem for guiding movement time of, the spring being received between a head 143 on said thimble and a flange 144 on said stem.

A brake 151 is provided for causing cessa tion of rotation of the drive shaft 85. This brake is shown as a cone brake, the cone member 152 thereof is on a sleeve 153, which is slidable lengthwise on the drive shaft and has spline key and groove connection 154 therewith. The socket member 155 of said brake is shown as a socket face on a cross wall 156 of the housing.

Centrifugal means are exemplified as acted on by the drive shaft for urging engaged relation in the brake. The centrifugal means are exemplifiedas comprising bell-crank-levers 158, pivoted respectively at 159 to a cage 160, shown provided with a hub fixed, as by a pin 161, to the drive shaft. The. arms 162 of the bell-crank levers are acted on by the centrifugal force due to rotation of the driving member for moving said arms outwardly. Springs 163 are located between said arms for normally drawing said arms toward the axis of rotation of the cage. These springs are exemplified as having their respecrive ends received about pins 16 i on said respective arms. The other arms 165 of said bellcrank levers have rounded ends 166 received in an annular groove 167 in the sleeve 153. The outward movements of the arms 162, due to centrifugal force, urge the brake into braking relation.

Control means resisting such. urging of the centrifugal means are shown as comprising a lever 171, pivoted about a pivot-rod 172, fixed in bearings 173 oi: the housing 88. This lever comprises arms 17 1 forming a fork, and having pivoted shoes 175 received in an annular groove 176 in the sleeve 153. The lever further comprises an arm179 from which a stem 180 extends, the stem being fixed in a bearing 181 in said arm.

This stem and the endwise movable stem 132 are provided with coacting latching faces, arranged respectively for resisting movement of the sleeve urged by the centrifugal force of the levers 158, and after such resistance has been released by disengagement of th clutch 101, in turn resisting reengagement oi? said clutch until rotation of the driving member of the clutch has ceased.

These latching means comprise a latching lug 182, against which a latching face 183 on the stem 180 is received for resisting centrit ugal movement of the lovers 158. \Vhenthe stem 132 is moved endwise, so as to move the latching lug 182 out or range of the latching face 183, and the centrifugally acting levers 158, are rotating, the outward thrust of the arms 162 of said levers, causes the swinging of the lever 171 on its pivot, causing engagement in the braking means, for stopping rotation of the driving shait. hen such rotation has ceased, the springs 163 cause retraction of said centrifugally operated arms for again releasing said brake, which in turn causes retraction of the lever 171 for reengaging the latch 182, 183.

During the time that the lever 171 has been released and swung upon its pivot by the movement of the braking sleeve in braking direction, the outer end of the lug 182 rests upon the face 18& of the stem 180, whereby movement of the clutch collar 103 in clutching direction is prevented, so as to hold said clutch collar in unclutching relation during the braking relation in the brake. When the brake sleeve returns to release relation in the brake, the latching member which holds the clutch collar in unclutching relation moves into unlatching relation, for movement of said clutch collar into clutching relation.

Means are provided for automatically disengaging the clutch or power connecting and disconnecting couple and for controlling the brake operation, exemplified as knock-out arms 191, 192, on a knock-out plate 198, rockable about a journal portion 19a of the gear 70, and held to said journal portion by the hub of the crank arm 68. (See Fig. 7.)

Resilient yield is permitted to the knockout arms upon contact with the lever 111, this contact being instanced as with the roller 126 on said lever. This resilient yield is for the purpose of avoiding shock and between the parts, and is shown effected by a spring 195. (See Figs. 3, 4, and 5.) The respective ends of the spring are received about a pin 196 on said knockout plate and a pin 197 on the gear 70, the' operating upon clamping relation and alsoupon unclamping relation in said clamp, and the clutch releasing means and the brake applying means have control means therebe tween for operation in the sequencev named.

The means for controlling operation of the motor, which are also preferably in synchronism with the clamp operation, are instanced as such as to operate interrupting means for interrupting the supply of power for the motor in such manner as to complete the cycle of movements for placing the clamp in clamping relation, and completing the cycle of movements for placing the clamp in unclan'iping relation, and prevent unintentional overthrow or repetition of said respective cycles.

The motor is instanced as an. electric motor, and the power supplying means are instanced as a suitable electric circuit for said motor. the power interrupting means being instanced as an electric translating device. instanced as a switch in said circuit, although it is obvious that other motive power, power supplying means and power interrupting means may be employed with out departing from the spirit of my invention within the scope of the appended claims.

The electric motor 91 is instanced in a main electric circuit- 201, including a suitable source of electric energy, as the generator in any suitable power circuit. A switch 202 is in this circuit, and is instanced as a mechanically operated switch. A switchoperated element 203 is also located in this circuit, and is controlled by a magnetic ele ment 204, forming a magnetic switch, the armature 205 of which forms or supports the electro-conductive part 203 of the switch. The magnetic element 204 of said magnetic switch is preferably in a bypass circuit 206. in which there is a manually operated switch 207. a partial circuit, the respective ends of which are connected to the main circuit at opposite sides of the magnetic switch, as at 208, 209. (See Fig. 17.)

In order that the magnetic element 204 may be magnetized by the main circuit to maintain the closed relation of the magnetic The by-pass circuit is shown as nects with the partial circuit 206 at 211 at one of its ends, the other end thereof leaving a terminal 212 adapted to be engaged by the contact-bar 203. The by-pass circuit 206 has a resistance coil 213 for insuring a decreased current in the by-pass circuit.

The magnetic element of the magneticswitch 1s located 1n a bypass or partial c1rcuit having two legs, in one of which the.

manually operated switch 207 is located for energizing the magnetic element and closing the magnetic switch, and the other leg of which connects with the main circuit for maintaining such magnetized condition and continuing the closed relation of the magnetic switch after release of the manually operated switch, and until the mechanically operated switch is opened, whereupon the magnetic switch opens and remains open until the next actuation of the manually operated switch 207. The circuit in the motor 91 is maintained until the switch 202 is released, whereupon the circuit in the magnetizing element fails and the magnetic switch is released. The circuit is instanced as, but not limited to, a normally open circurt. I

The switch 202 is instanced as comprising an arm 215 having a bearing 216 journaled to a stud-shaft 217, fixed in a switch-box 218 secured to the lower end of the column 23. This arm carries the electro-conduct1ve con tact part 219 of the switch 202, insulated by an insulation plate 220. The contact-part 219 is arranged to contact the coacting electric contacts 221 in the main circuit.

An arm 225 is integral with the arm 215 and has a heel 226. A spring 227 between said heel and the stationary wall 228 of the switch-box 218, normally urges contact between said contacts.

Means are provided for automatically operating said switch for deenergized conditionvot the electric motor, accomplished in the present instance by having the roller 126 strike the arm 225 for moving the contact 219 from the contacts 221, and thereby opening the circuit and deenergizing the magnetic switch or translating device and the motor. An adjustment is provided for adjusting the moment of release of said switch, shown as a set-screw 229 threaded in a threaded hearing 230 on the arm 225, a jam-nut 231 holding the set-screw in adjusted positions.

The magnetic switch is shown at thebase of the machine. The manually operated switch is preferably on the drill-arm, and is instanced as mounted on the drill-slide, so asto be moved laterally with the drill-slide on the drill-arm.

Means are further provided in the'motor control means for compensating for the various lateral positions to which the drill-slide may be adjusted and the various elevations to which the drill-arm may be'adjnsted, comprising for instance, automatic take-up means 234, exemplified as at the base of the drilling machine. The take-up means may comprise a spool 235, provided with electroconductive contact rings 236, 237, with which the electric conductors of the partial circuits 206 are connected by binding posts 238, 239. The spool is preferably of insulating material.

The spool rotates about a stud-shaft 240, shown fixed to the clamp bearing at the lower end of the rotatable column. The spool isheld endwise to the stud-shaft by a washer 241 and a nut 242 received about the thread ed reduced end of the stud-shaft. A spiral spring 243 is received about the stud-shaft, one end thereof being received in a hole in the column, and the other end being-received in a hole in the spool. Electric contacts 244, 245, urged by springs 246, coact with the rings on the spool, and are received in insulating blocks 247, 248, and have binding posts 249, 250, to which the continuations of the electric conductors forming the partial circuit 206 are secured. These electric conductors are flexible electric conductors.

The spring 243 automatically takes up the slack which may be in the electric conductors 206, between the drill-slide and the take-up means. The flexible electric conductors-may be encased in a cable 253 extending between the switch 207 on the drill-slide and the takeup means, and be directionally guided over a sheave 254, rotatable about a stud 255 fixed to the bearing 26 of the drill-arm about the column.

In explaining the operation of our improved device, it may be assumed that in the present exemplification of our invention the clutch 101 is normally in engaged relation for transmitting motion from the motor to the operating means for the clamp, and that the brake 151 is normally in release relation for permitting such operation, and that the mechanically operated switch 202 is normally closed, and the magnetic switch 203 and manually operated switch 207 are normally open.

\Vhen it is desired to clamp or to unclamp the radial drill-arm, the operator, whose position is in front oi ,'or at the drill-slide, manually presses the button of the switch 207 in the partial circuit or by-pass circuit 206, which energizes the field in the magnetic switch 203 for closing the same, and thereby completes the main circuit or motor circuit for operation of the electric motor. The closing of the magnetic switch causes continuation of energizing of the field magnetic switch by means of the main circuit, whether or not the operator continues to press the button of the manually operated switch. The operator may at once release said button, as the by-pass or partial circuit is completed into the main circuit through the leg 210 of theby-pass circuit.

Acompletion of the cycle of movements of the clamp operating means for placing "the clamp in clamping relation, or respectively in unclamping relation, is thus assured. I

' A continuation of clamp operation after the desired clamping or unclamping condition respectively hasbeen attained, is prevented. This is effected by positive means actuated in synchronism with the clamp operation, by the means provided for opening the mechanically operated switch 202, which opens the motor circuit and also deenergizes the field of the magnetic switch for opening the latter and replacing the motor control parts in normal relation for a next sequential operation n theclamping means. The

clutch is disengaged, instanced as accomplished by the knockout arms engaging the lever 111, the spring 195 avoiding shock to the parts and the pin 199 limiting theyielding movement of the knock-out arms so as to cause definite relation of clutch disengagement to angle of crank-arm rotation.

The clamping relation of the clamp is preferably such that a right linedrawn through the axis of rotation of the eccentric and the high point of the eccentric is parallel with the line of clamping power between the cheeks at the respective sides of the split bearing, being exemplified as parallel with the link 47, as shown by the dot and dash line 0. (See Figs. 12 and 14.) This relation insures a maintenance of clamping action of the clamp for maintaining the radial drill-arnr in adjusted radial position.

Themeans for operating the clamp are also preferably such that a right line, exemplified by the dot and dash line cl, (see Fig. 14-) will intersect the axis of rotation of the crank-arm and the axis of the crank. and be substantially parallel with the link 78, preferably also bisecting the axis of articulation between said link and the arm 55, when the clamp is in clamping relation.

In the present exemplification, the clamping action and the unclamping action are alternately effected by successive manual operations of the switch 207, and by successive operations of the means described for operating the crank-pin 67. At a given half revolution of the crank-arm 68, theclamp is moved from an unclamped relation, such as shown in Figure 13, to a clamp relation, such as shown in Fig. 14 and at the next half revolution of the crank-arm 68 in the same direction, the clamp is moved from the clamped relation, such as shown in Fig. 11 to an unclamped relation, such as shown in Fig. 13. The arm reci rocates between the positions shown in Figs. 13 and 14:, whereby the eccentric 13 is moved into the respective relations shown in said figures.

As soon as, clutch disengagement takes place rotation of the crank-arm ceases re gardless of continuation of power in the electric motor and regardless of switch relation.

It is desirable however, that rotation of the driving member of the clutch shall be reduced or cease as quickly as possible, so as to make clutch reengagement convenient for speedy repeated crank actuation. The knock-out arms are therefor also instanced as operating the switch 202 and as causing actuation of the brake.

The sequence of operation of the clutch releasing means, the switch operating means and the brake applying means, is preferably in the order named, as it is desirable to first release the clutch, so as to disengage the power from the clamp operating means, then to open the motor circuit for cessation of power application to the motor, and to then stop rotation of the rotor. As soon as rotation of the rotor for clutch actuation begins, centrifugal force is applied to the centrifugal arms 162. Centrifugal movement of these arms is however prevented by the holding means 132, 180, until clutch release has been substantially perfected. Adjacent to, or at, the completion of the clamp operation, one of the knock-out arms 191, 192, actuates the lever 111, for releasing the clutch, whereupon driving of the clamp operating means immediately ceases and the clamp operating means are locked in actuated relation due to the meshing relation between the worm 81 and the worm wheel 70, and the relations of the crank 68 and of the eccentric 43. l V

The operation of the lever 111 also causes actuation of the switch 202, and release of the holding means 132, 180. The release of the holding means, which normally hold the centrifugal arms in unactuatcd relation, release said centrifugal arms, whereupon the brake 151 is applied for causing cessation of rotation of the driving member of the clutch, the rotor of the motor and the drive shaft 85. Upon substantial cessation of such rotation the centrifugal arms are drawn toward each other by means ofthe springs 163 for again releasing the brake.

When the holding means 132-180,,are released and the centrifugal arms are spread, the latch part 180' assumes an interfering position with relation to the latch part 182, for holding the clutch 101 in release relation as long as said brake is applied, that is, until cessation of rotation of the driving clutch part, the rotor and the drive shaft. Upon cessation of such rotation the centrifugal arms move toward each other for releasing the brake and moving the latch part 180 out of interfering relation with the latch part 182, for permitting the clutch to reengage under the influence of the spring 140.

Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent, is:

1. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member, power means for driv ing said driving member, power interrupting means for the latter, a releasable driving connection between said driving member and said clamp, a brake for said driving member, and means operating in synchronism with said clamp for causing interruption in said power interrupting means,

releasing said driving connection and operating said bralie.

2. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for V clamping said toolarm in adjusted positions,

a driving member, power means for driving said driving member, power interrupting means for the latter, a releasable driving connection between said driving member and said clamp, said releasable driving connection normally in connected relation, a brake for said driving member, means operating in synchronism with said clamp for causing interruption in said power interrupting means releasing said driving connection and operating said brake, and means automatically returning said releasable driving connection to connect-ed relation.

- 3. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, comprising a rotatable member rotating in the same direction for clamping and for unelamping said tool-arm, a driving member, power means for driving said driving member, power interrupting means for the latter, a releasable driving connection between said driving member and said rotatable member, a brake for said driving member, and means operating in synchronism with said clamp for causing interruption in said power interrupting means, releasing said driving connection and operating said brake.

4 In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member, JOWGI' means for driving said driving mem er, power interrupting means for the latter, a releasable driving connection between said driving member and said clamp, said releasable driving connection normally in connected relation, a brakefor said driving member, said brake normally in unbraking relation, means operating in synchronism with said clamp for causing interruption in said power interrupting means, releasing said driving connection and operating said brake, and means automatically returning said driving connection and said brake to normal relations.

5. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member, a brake normally in released relation, centrifugal means operated by said driving member for placing said brake in braking relation, means restraining said last-named means, and means operating in synchronism with said clamp for releasing said restraining means.

6. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member, a releasable driving connection between said driving member and said clamp, a brake, centrifugal means for operating said brake, and means operating in synchronism with said clamp for controlling the release in said driving connection and operation of said brake.

7. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member for said clamp, a brake for said driving member, centrifugal means for operating said brake, and means operating in synchronism with said clamp for operation of said brake.

8. In a radial drilling machine the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in ad j usted positions, a driving member, a releasable driving connection between said driving member and said clamp, a brake for said driving member, centrifugal means for operating" said brake, means operating in synchronism with said clamp for releasing said driving connection, and control means between the latter and said brake resisting said centrifugal means.

9. In a drilling machine, the combination of a base, a toolarm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member, a releasable driving connection between said driving member and said clamp, a brake for said driving member, centrifugal means for operating said brake, holding means resisting said centrifugal means, and means operating in synchronism with said clamp for releasing said drivingconnection and said holding means. 10. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member, a releasable driving connection between said driving member and said clamp, a brake for said driving member, centrifugal means for operating said brake, holding means resisting said centrifugal means, means operating in synchronism with said clamp for releasing said driving connection and said holding means, and means automatically returning said driving connection and said holding means to normal relations.

ll. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a driving member, a releasable driving connection between said driving member and said clamp, a brake for said driving member, and holding means between said releasable driving connection and said brake holding said brake in release relation during,

operative connection in said releasable driving connection and permitting braking relation in said brake during release relation in said driving connection.

12. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping sa d tool-arm in adjusted positions, a releasable driving connection between said driving member and said clamp, a brake for said driving member, centrifugal means for operating said brake, and holding means between said releasable driving connection and said brake normally resisting said centriiuga] means and arranged to hold said releasable driving connection in release relation upon actuated relation in said centrifugal means.

13. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm is adjusted positions a releasable driving connection between said driving member and said clamp, a brake for said driving member, centrifugal means for operating said brake, holding means between sa d releasable driving connection and said brake normally resisting said centrifugal means and arranged to hold said releasable driving connector in release relation upon actuated relation in said centrifugal; means,

couple in disconnecting relation and said braking means in braking relation.

15. In a drilling machinc,,the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, means for operating said clamp comprising a driving member, a power connecting and disconnecting couple operatively disposed between said driving member and said clamp, said couple normally-in connected relation, braking means for said driving member, and knock-out means operatively connected with said clamp automatically placing said couple in disconnected relation, and said'brake in braking relation.

16. In a drilling machine, the combination ofa base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, means for operating said clamp comprising a motor, a releasable driving connection between said motor and said clamp comprising a driving member, a. brake for said driving member, power supplying means for said motor, power interrupting means for the latter, and means in synchronism with said clamp for controlling said last-named means, for releaseot said driving connection, and for operation of said brake.

17. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, means for operating said clamp comprising a motor, a releasable driving connection between said motor and said clamp comprising a driving member, a brake for said driving member, power supplying means for said motor, power interrupting means for the latter, means in synchronism with said clamp for controlling said lastnamed means, for release of said driving connection, and for operation of said brake, and automatic means returning said power interrupting means, said releasable driving connection and said brake to normal relations.

18. In a drilling machine, the combination Ill of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp 't'or clamping said tool-arm in adjusted positions, a motor, a clutch between said motor and said clamp comprising a driving member, a brake for the latter, centrifugal. means for operating said brake, power supplying means for said motor, power interrupting means for the latter, and means in synchronism with said clamp for operating said power interrupting means, for releasing said clutch and engaging said brake.

19.- In a drilling machine, the combination of a base, a tool-arm a ljustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, a motor, a clutch between said motor and said clamp comprising adriving member, a brake, centrifugal means for operating said brake, clutch releasing means, resisting means between said clutch releasing means and said centrifugal means, power supplying means for said motor, power interrupting means for the latter, and means in synchronism with said clamp for releasing said clutch, interrupting said resisting means for engagement of said brake, and actuation of said power interrupting means.

20. In a drilling machine, the combina tion of a base, a tool-arm adjustable to radial positions with relation thereto,a clamp for clamping said tool-arm in adjusted positions, 21 motor, a clutch between said motor and said clamp comprising a driving member, a brake, centrifugal means for operating said brake, clutch releasing means, resisting means between said clutch releasing means and said centrifugal means, power supplying means for said motor, power interrupting means for the latter, means in synchronism with said clamp for releasing said clutch, interrupting said resisting means for engagement of said brake, and actuation of said power interrupting means, and means automatically returning said clutch into engaged relation, releasing said brake and returning said power interrupting means to normal position.

21. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, an electric motor for operating said clamp, electric control means for said motor comprising a magnetic switch, a manually operated switch for controlling said magnetic switch, and a knock-out switch, and knock-out means operatively connected with said clamp for opening said knock-out switch, and thereby interrupting the current in said motor, and releasing said magnetic switch.

22. In a drilling machine. the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a

clamp tor clamping said tool-arm in adjusted positions, means for operating said clamp comprising a'driving member, a power connecting and disconnecting couplc operatively disposed between said driving member and said clamp, said couple including a movable member, controlling driving relation in said couple, moving means for said movable member, a brains. for a member of said couple, said moving means, and said brake having control means therebetwcen, said control means including stops for respectively maintaining said brake in unbraking relation, and said couple in disconnecting relation.

23. In a drilling machine, the combination of a base, a toolarm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, means for operating said clamp comprising a motora power connecting and disconnecting couple between said motor and said clamp, a brake for said motor, said couple and said brake having control means therebetwecn for normally maintaining said brake in unbrakingrelation and for normally maintaining said couple in disconnected relation, and centrifugally operated means for said control means.

24. In a drilling machine, the combination ofa base, a t0ol-arm adjustable. to radial positions with relation thereto, a clamp lor clai'i'iping said tool-arm in adjusted positions, means for operating said clamp comprising a motor, a power connecting and disconnecting couple operatively disposed between said motor and said clamp. a brake for said motor, centrifugal means for operating said brake, control means between the latter and said couple, and knockout means operatively connected with said clamp controlling said last-named control means.

25. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, means for operating said clamp comprising a rotatable member, a power connecting and disconnecting couple operatively disposed between said motor and said rotatable member and comprising a driving member, a brake for said driving member, centrifugal means for said brake, means normally holding saidcouple in connecting re lation. means between the latter and said centrifugal means normally resisting centrifugal action in said centrifugal means. and knock-out means connected with said rotatable member for automatically placing said couple in disconnecting relation and automatically releasing said centrifugal means for placing said brake in braking relation.

26. In a drilling machine, the combination of a base, a tool-arm adjustable to radial po ill) sitions with relation thereto, a clamp for clamping said tool-arm in adjusted positions, means for operating said clamp comprising a rotatable member, a power connecting and disconnecting couple operatively disposed between said motor and saidrotatable member, said couple comprising a driving member, a brake for said driving member, centrifugal means for said brake, means normally holding said couple in connecting relation, means between the latter and said centrifugal means normally resisting centrifugal action in said centrifugal means, knockout means connected with said rotatable member for automatically placing said couple in disconnecting relation and automatically releasing said centrifugal means for placing said brake in braking relation, and automatic means returning said couple into connecting relation, and said brake into release relation.

27. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions with relation thereto, a clamp tor clamping said tool-arm in adjusted positions, means for operating said clamp comprising an electric motor, and means operated thereby arranged for cycles of damp ing movement and unclamping movement in said clamp, said electric motor normally deenergized, an electric translating device for energizing of said motor, and knock-out means for the latter operating in synchro nism, with clamped relation and. with unclamped relation respectively, in said clamping means for deenergizing said electric motor at each of said relations for insuring completion of each cycle of movement of said operating means for said clamping device.

28. In adrilling machine, the combination of a base, a drill-arm adjustable to radial positions with relation thereto, a drill-slide adjustably laterally on said drill-arm, a clamp for clamping said drill-arm in adjusted positions, an electric motor for operating said clamp, a magnetic switch and a mechanically operated switch controlling the same, a circuit in which the magnetizing element of said magnetic switch is contained, automatic means for operating said mechanically operated switch, and a manually operated switch in said circuit supported by said drill-arm. I

29. I11 a drilling machine, the combination of abase, a drill-arm adjustable to radial positions with relation thereto, a drill-slide adjustable laterally on said drill-arm, a clamp for said drill-arm, an operating de vice at said base for said clamp, an electric motor for operating said operating device, a magnetic switch at said base controlling said electric motor, a partial circuit in which the magnetizing element of said ma switch is contained, and a manually operated switch in said partial circuit supported by said drill-arm.

80. In a drilling machine, the combination of a base, a. drill-arm adjustable to radial positions with relation thereto, a drillslide adjustable laterally on said drill-arm, a clamp for said drill-arm, an operative device at said base for said clamp, an electric motor.

for operating said operating device, a magnetic switch at said base controllingsaid electric motor, a partial circuit in which the magnetizing element of said magnetic switch is contained, and a manually operated switch in said partial circuit having operative connection with said drillslide for moving laterally therewith.

31. Ina drilling machine, the combination of a base, a drill arm adjustable to radial positions with relation thereto, a drilla-slide adjustable laterally on said drill-arm, a clamp for clamping said drill-arm in adjusted positions, an electric motor for operating said clamp, a magnetic switch controlling the same, a partial circuit in which the magnetizing element of said magnetic switch is contained, and a manually operated sv.-':.lch in said partial circuit having operative connection with said drill-slide for moving laterally therewith.

32. In a drilling machine, the combination of a base, a drill-arm adjustable to radial positions with relationthereto, a drill slide adjustable laterally on said drill-arm, a clamp for clamping said drill-arm in adjusted positions, an electric motor for operating said clamp, a main circuit therefor including a mechanically operated switch, a magnetically operated switch element in said main circuit, a partial circuit controlling the latter, a manually operated switch in said partial circuit having operative connection with said drill-slide for moving laterally therewith, and a knock-out member for said mechanically operated switch having an operative connection with said clamp.

In testimony whereof, we have hereunto signed our names.

ALBERT E. ROBINSON. AUGUSTUS M. SOSA.

Hill 

